Screw thread cutter attachment



June 8, 1937. I

Fig.].

H. RIESTER SCREW THREAD CUTTER ATTACHMENT Filed July 13, 1956 IH'H K0 QQ 1) I 2 Sheets-Sheet l E 'ij Hubert Ries ter A? TORNEYS June 8,- 1937.RlEsTER 2,083,473

SCREW THREAD CUTTER ATTACHMEfiT Filed July I3, 1956 2 Sheets-Sheet 2Fig.2.

ATTORNEYS threads of different sizes can be cut in the work PatentedJune 8, 1937 UNITED STATES PATENT OFFICE SCREW THREAD CUTTER ATTACHMENTHubert Riester, Collingswood, N. J.

is 4 Claims.

The invention relates to a screw cutting attachment and more especiallyto screw thread attachments for bench lathes.

The primary object of the invention is the provision of an attachment ofthis character, wherein the thread cutting tool and the work can beadjusted so as to regulate the size of threads to be cut through the useof but one master screw, there being an indicator which will identifythe character of thread cut in the work andsuch indicator is readily andeasily set in conformity with the requirement of thread to be cut. I

Another object of the invention is the provision of an attachment ofthis character, wherein the same is applicable to a bench lathe so thatscrew and accuracy had in the cutting of such threads in conformity withthe size required, the attachment being novel in its entirety and issusceptible of a wide range of adjustment.

A further object of the invention is the provision of an attachment ofthis character, which is simple in its construction, readily and easilyapplied to a bench lathe for the service thereof in cutting threads ofdifferent sizes, easy of adjustment, thoroughly reliable and efficientinits operation, and inexpensive to manufacture and install.

With these and other objects in view, the invention consists in thefeatures of construction, combination and arrangement of parts as willbe hereinafter more fully described, illustrated in the accompanyingdrawings, which disclose the preferred embodiment of the invention andpointed out in the claims-hereunto appended.

In the accompanying drawings:

Figure 1 is a top plan view of a bench lathe showing the attachmentconstructed in accordance with the invention applied.

Figure 2 is a fragmentary side elevation thereof.

Figure 3 is a vertical transverse sectional view through the attachment.

Figure 4 is a sectional view on the line 4--4 of Figure 3.

Figure 5 is a sectional view on the line 5-5 of Figure 3. V

Figure 6 is a perspective view of an adjunct of Figure 5. I

Similar reference characters indicate corresponding parts throughout theseveral views in the drawings.

Referring to the drawings in detail, A designates generally a benchlathe havinga pedestal l carrying a bed I l on which is adjustablyfitted a head stock l2 and a slide rest l3, respectively, the said sliderest being adapted for cross adjustment as well as longitudinaladjustment on the bed while the head stock I2 is susceptible ofIongitudinal adjustment upon said bed.

Application July 13, 1936, Serial No. 90,436

(o1. sz-m- V The head stock l2 has journaledtherein a chuck spindle l4fitted with a suitable chuck l for work, an example of the latter beinga bolt as indicated at 16. The slide rest 13 has therein a tool spindleI! operating a thread cuttingcutter l8, the spindle ll being also fittedwith a pulley IQ for a drive belt (not shown).

Upon the bed II is fixed rearwardly of the head stock I2 a guide saddle20 formed with the upwardly directed pairs of guide eyes 2| and 22,respectively, which are arranged spaced apart at opposite sides of thelathe bed H and in which are fitted slide rods 23 and 24, respectively.

Fixed to the saddle 20 is a bracket 25 formed with a horizontallydisposed guide barrel 26 in whichds rotatably fitted the threaded stem21 of an adjusting knob 28, the stem 21 being threaded in a follower 29slidably fitting the barrel 26. The follower 29 carries a combinedindicator and. fulcrum pin 39 projected upwardly through an elongatedslot 3| provided in the top of the said barrel 26. This barrel 26extends laterally of the lathe A from one side thereof, that is,outwardly from the front side of the lathe.

The stemg21 has formed therein next to the knob 28 an annular channel orgroove 3| in which fits a key 32 acted upon byya setting screw 33 sothat the said stem 2'! can be rotatably latched within the barrel 26 andalso can be frictionally bound when the knob 28 is set at a determinedadjustment of such stem in locating the pin in the slot 3! in saidbarrel for altering the fulcrum position of suoh'pin.

'Fitted on theslide rod 23 is an adjustable clamp 34 for the mounting ofa gage bar 35 which extends over the barrel 26 and is formed with a slot36 for accommodating the pin 30, it having an indicator mark 31 in itstop for coaction with a scale 38 provided on the upper side of the bar35,.- The bar 35 is swingingly fixed to the clamp 34 by a holding screw39 threaded in' a boss 40 formed on said clamp and working against acrowning washer 4| above said bar 35. This screw 39 coacts with aclamping key 42 for the locking of the clamp 34 upon the rod 23.

Clamped upon the rod 24 isa cross head 43 while fixed to the chuckspindle l4 in the head stock I2 is a master screw 44, the said crosshead 43 being in threaded engagement with the master screw and suchcross head is adjustably secured to the rod 24 by the screw 45 while thethreaded engagement of the said cross head with the master screw 44 isbad by the screw 46.

The cross head 43 has provided in its upper side intermediate and outerthreaded sockets 41 and 48, respectively, which are spaced from eachother and selectively engageable therewith is a pivot screw 49selectively insertable in holes 50 provided in the bar 35 and companionsto the sockets 41 and 48 so that by altering the pivot screw 49 in thesaid bar 35 and cross head 43 the throw of the rod 23 will be changed.

The rod 23 has fitted thereto a laterally adjustable fork 5| engageablewith an annular shoulder 52 formed on the arbor for the thread cutter l8and thus when the rod 23 is shifted the cutter I8 is correspondinglymoved therewith and in this manner the threads 53 cut in the work l6,said cutter being regulated in conformity with the setting of the pin 31with respect to the scale 38 upon the bar 35, the knob 28 beingperipherally marked with a setting scale 54 having a calibrationconsistent with the scale 38 and in this manner the attachment can beset and will indicate a chan e, inthe number of threads to be out inchoii the work l6, the threads being indicated at 53 on'this piece ofwork.

Thegusezof the single master screw 44 in the attachment enables one toobtain'from thirtysix threads per inch to one hundred and fifty threadsthereof, themaster'screwbeing equipped with the eighteen threads perinch and by substituting a thirty-two thread per inch master screw therange of threads per inch on the work will be from one hundred and fiftyto three hundred threads per inch as cut by the adjustfiieht or the bar35 upon the cross head 43 and the changing: of the pin 31 throughmanipulation of the knob 28.

The master screw 44 has fixed thereto a hand turning wheel 55, the chuckspindle l4 being fitted as usual with a stepped grooved speed belt'fiiilley'56 for a drive belt (not shown).

fork 5| is' susceptible of adjustment on the red 23' and also slide restI3 is adjustable in conformity with the size of the work for threadcutting; thereof. 7 v V The bar 35' constitutes a throw lever for therod 23 and the throw of the lever under the settin fih fof varies theposition of the thread cuttf v I8 in conformity with the sizes of threadcutting of such work as may be required. The master screw 44 is thefeeder for the throw of the bar or lever 35 the extent of throw of thelatter being regulated by the positioning of the pivot pin 48 selectivelin the sockets 41 and 48 and holes 50, respectively.

'I'hefork 5| is held fast in its adjustment on tagged :3 by a bindingscrew 56.

The master screw 44 at its outer end is journaled in' a hanger 51 formedwith one of the 2| or the saddle 2n, the bracket 25'being' seeiifed inplace by a fastener 58. The screws 33, 38 and 49 are preferably providedwith knurled heads 59 to permit easy adjustment thereof.

ihestm 21 or the knob 28 is fitted in a bushing '60 confined within thebarrel 26 and having a clearance 6 I for the key 32, the pin 30 beingthe fulcrum for the bar or lever 35. Thispin 30, as before stated, isshiftable to change the fulcrum point of the bar or lever 35'accordingto the size of the thread to be cut in the work. At the uppermost sideof the barrel 26 next to the knob 28 is a pin 62, it having an indicatormark 63 for coaction with a scale 64 provided periphing the said knob 28by hand.

changeable fulcrum for the throw arm and fitted with the saddle, acutter carried by the slide rest, a connection between the cutter andthe said other rod for regulatYng the cutting action of said cutter onwork heldwith the chuck, and means for changing the fulcrum;

2. In a lathe, a slide rest, a head stock, a rotary spindle in the headstock and having a chuck, a stationary saddle rearwardly of the stock,-slide rods in Said saddle on opposite sides of the spindle, a cross headfitted to one rod, a master screw connected with said spindle andthreaded in the cross head, a throw arm selecti-vely pivoted to thecross head, means swingingiy connectin the throw arm to the other rod, achangeable fulc'i 'uni for the throw arm and fitted with the saddle, acutter carried by the slide rest, a connection between the cutter andthe said other rod for regulating the cutting action of said cutter onwork held with the chuck, means for'changing' the fulcrur'n, and a handwheel fix'e'd to said spindle.

3; In a lathe, a slide rest, a head stock, a rotary spindle in theheadstock and having a chuck, a stationary saddle rearwardly of thestock,- slide rods in said saddle on opposite sides of the spindle, across head fitted to one rod, a niastr screw connected with said spindleand threaded in the cross head; a throw arm selectively pivoted to thecross head, means swingingly connecting thethroy'v' arm to the otherrod, a changeable fulcrum for the throw arm and fitted with-the saddle,a cutter carried by the slide rest, a connection between the cutter andthe said other rod for regulating the cutting action of said cutter onwork held with the chuck, means for changing the fulcrum, a hand wheelfixed to said spind-le, a scale on said arm, and an indicator onthefulcrum for cooperation with the scale.

' '4; Iii a lathe, a slide rest, a head stock, a rotary spindle in thehead stock and having a chuck, a stationary saddle rearwardly of thestock, slide rodsin said saddle on opposite sides of the spindle, across head fitted to one rod, a master screw connected with said spindleand threaded in the cross head, a throw arm selectively pivoted to thehead, means swingingly connecting the throw arm to the other rod, achangeable fulcrum for the throw arm and fitted with the saddle, acutter carried by the slide rest, a' connection between the cutter andthe said other red for regulating the cutting action of said cutter onwork held with the chuck; means for changing the fulcrum, a hand wheelfixed to said spindle,

a scale on said ar iii, an indicator on the fulcrum for cooperation withthe scale, and a setting dial included with the means for changing theful- HUBERT RIES'I'ER.

